We've been talking at cross purposes, then.  When you said "This is exactly what I am trying to achieve", I took that as a reply to my question "What are you trying to do - update the table to turn mm into inches?"  As I mentioned, I'm afraid I don't know enough about VB code to be able to help you with doing it the way you're doing it.  What I would do is drag the data out of the database in mm, with no conversions whatsoever, and have your front end convert to inches (and back to mm where there is an update).

John